Artificial teeth



Aug. 11, 1936. A. GYSI ARTIFICIAL T-EETH Filed July 17, 1935 2Sheets-Sheet 1 INVENT R Patented Aug. 11,1936

UNITED STATES PATENT OFFICE aososs'z ARTIFICIAL TEETH Alfred and,Zurich, Switzerland, "minors to The Dentists Supply Company of New York.New York, N. 1., a corporation of New York Application July r1, 1935,Serial No. class 4 Claims. (01. 32-8) This invention relates toartificial teeth and particularly to artificial teeth which willarticulate and, in so doing, work in harmony with the movements of theJaws of the average human being; I

In my United States Patent No. 1,665,357, dated April 10, 1928, therewere explained methods and means for making primordial forms bygeometrical construction that would harmonize with the' averagemovements of the human mandible during mastication.

- In that patent, the cutting of the teeth from the primordial tothefinished stage was shown, 7 and the teeth were made to inter-relate onthe facetsof the primordial forms, but with the elevations and deepdepressions removed and rounded so as to reduce the contact areas of theoriginal primordial forms and, at the same time, to provide fossae andsulci for the reception and go elimination of food during mastication.

The present invention relates to teeth designed from similar primordialforms but in which the fossae and sulci have been carved to present amore emcient masticating instrument. One of the objects of thisinvention is to provide artificial teeth which have more definitecutting and shearing contacts, upper with lower. Another object of theinvention is to provide artificial teeth having such definitecharacteristic o primordial inter-relating contact areas retained ;as todefinitely assist the dentist in the proper placement of uppers-withlowers. A still further object of the invention is to arrange orposition the reliefs in the upper facets with relation to the reliefs inthe lower facets as -45 position.

Another object of the invention is to so form the neck areas ormarkingsof the buccal surfaces that proper identification is provided for therec- I ognition offirst or second bicuspids or molars. so According tothis invention, the facets of the upper and lower primordialforms arecut to geometrical design so as to correspond during mandibular movementwith average human Jaw movements, and as the peripheries of these facetscon- ;Qii tacteach other theyform definite angles which are retained asvital features of this particular, design. so thatv the teeth caneventually be set in exactly the relative position .to which they werecarved, whereas the fossae and sulci are cut from the interior of thefacets, not disturbing th con- 5 trolling areas, but retainingtheperipheral outlines of the facets as they were cut on the primordialform.

The drawings illustrate an embodiment of the invention and the viewstherein are as follows: 10

Fig. 1 shows aprimordial form from which the occlusal surface of theleft lower posterior teeth are to be carved, I s

Fig. 2 is a like view showing division of the primordial form intoindividual tooth blocks or units. 5

Fig. 3 shows the outline of the occlusal surface of one of thesedevices,

Fig. 4 is a like view of the finished tooth carved from-the block shownin Fig. 3, and which said tooth is the first lower left molar. 20 Fig. 5is a top plan view showing the occlusal surface of the first left uppermolar in primordial form,

Fig. 6 is a similar view showing a further development of theprimordial, form of Fig. 5,.

' Fig. 7 is a still further development showing th finished first leftupper molar,

Figs. 8 and 8-A represent the first upper and first'lower' molars beforereferred to, cross-sectioned from I to VII, said cross sections being somade in both teeth according to their position in centric articulation,

Figs. 9 to 15, inclusive, show the inter-relation of the upper to thelower first molars at the vari-- ous cross sections marked from I toVII, em- 35 phasizing the efiiciency as masticating tools,

Figs. 16 to 19, inclusive, are sections showing the movement and resultprogressively in the masticating of food through one of these crosssections,

Fig. 20 illustrates the continuous passage that v is formed between thetwo rows of teeth, upper and lower, due to the inter-relation of the cutout areas, which inter-relation facilitates the fiow of food to theoutside of tooth contacts, buccally and lingually,

Figs. 21 to 31, inclusive, show the tool-like action of this form oftooth carving, and

Figs. 32 to 35,-lnclusive, are buccalviews of the lower left posteriorteeth showing collar markings.

Whilenatural teeth, which are fixed by their roots in the mandible andin the maxilla, of the averagehuman do more or less deviate from acondition wherein all the teeth of the lower 'Jaw are in contact withthe corre p nding teeth of the 5s upper jaw during masticatingmovements, it has been found that with artificial teeth on plates whichare designed to take the place of lost natural teeth it is essentialthat these artificial teeth shall be so shaped and placed that the teethof the lower denture will contact with the corresponding teeth of theupper denture during the masticating movement in such a way as to formtool-like cutting, grinding and shearing instruments.

While the natural supposition would be tha natural teeth themselvesshould be copied, research has definitely ascertained that artificialteeth made in this way have a. very limited masticating power. It hasbeen learned through investigations and through long courses ofexperiments that posterior teeth should be made much more mechanicallyperfect in operation than natural teeth, because there is a greatdifference in the force or power that can be exerted by natural teeth ascompared with that which can be exerted by artificial teeth. Since thenatural teeth are firmly fixed in the bones of the mandible and maxilla,much greater force can be exerted in the masticating operation than canbe produced by an artificial denture which is much less firmly fixed inposition, because artificial teeth being. mounted on plates restingon'the mucous membrane are incapable of transmitting the samemasticating force as natural teeth, and thus they should be soconstructed that their cutting and grinding capacities are increasedwith less power than is usually available with natural teeth.

In my patent hereinbefore referred to, I have illustrated and describeda method for the production of primordial forms of the posterior teethwhich consists in securing to one member of an articulator two rows ofcutting knives arranged in a curve corresponding to a natural back toothrow at one side of the row and in more or less parallel relation, andhaving cutting edges which slope backward and downwardwith a graduallessen ing obliquity from front to rear; and thereafter, causing arelative movement between the knives corresponding to the left and rightside bite movements and to the forward or protrusive movements andbackward or retrusive movements, and to all possible movements of thearticulator corresponding to intermediary masticatory directions,so thatangular depressions and elevations are cut in and upon the primordialform which serve as the basis for the occlusal surfaces.

In the present invention, the primordial forms are obtained in likemanner and, for instance, by the use of an articulator such as thatshown and described in my German Patent No. 293,074, or in my UnitedStates Letters Patent No. 1,684,393, dated September 18,- 1928. Thisprimordial form for the left posterior teeth is shown in Fig. 1 of thedrawings.

Fig. 2 of the drawings shows this same primordial form divided intoindividual primordial forms on which the outlines'of the teeth are laid,as shown by the single first lower molar in Fig. 3.

In Fig. 3, the outline ll of the first lower left molar confines orembraces definite facets, e. g.,

42, N, U, 45, ll, etc., and these facets meet to form substantiallyV-shaped angulations either in the form of ridges or grooves.

In the form of teeth contemplated by my Patent lid-1,665,357, theangulations of the primordial forms were carved so that the meetingfacets were slightly rounded insofar as the ridges were concerned, andthe grooves were more'deeply carved to provide fissures for theeiilcient shearing and grinding of the food between the same and to alsoprovide means for the esc'apement of the food buccally and lingually.

In the figures of the drawings, the buccal side 6 of the forms and ofthe teeth illustrated is indicated by the character B, and the lingualside of form, that is to say, the angulations between the facets areretained in'both the lower and upper teeth, these angulations formingsurfaces for the inter-relation of the upper and lower teeth in 15 theirworking, balancing, protrusive and retrusive movements.

Figs. 5, 6 and 7 show the development of the first upper left molar fromthe primordial form to its finished condition, and Fig. 4 shows thefinished condition of the lower left first molar.

These finished first molars have their buccal and lingual sides roundedto the shape of the average natural tooth and are provided with beautymarks, etc., to givethem an appearance approximating that of naturalteeth.

The facets of the teeth have been provided with fossae 41 formed byremoving or digging out the face of the facets within the perimetersthereof, and sulci l8 have been formed for the escapement 30 ofmasticated food by providing fissures through certain of the angulationsor perlmeters of the facets, as clearly shown in Figs. 8 and 8--A.

In this figure, M represents the mesial side of the teeth and Drepresents the distal side. It will, of course, be understood that whenthese teeth are placed in proper plates, the tooth of Fig. 8 will berotated forward through 180 degrees so that its occlusal surface willinteract with the occlusal surface of the lower left first molar shownin Fig. 8-A which is centric position.

Now considering that these two teeth of Figs. 8 and 8A have been broughtinto centric coacting relation, the sections LP! to TIL-VII indicatesections cut down through both teeth in their centric position, that isto say, the line 1-1 of Fig. 8 will coincide with the line I-I of Fig.8-A, and the other lines accordingly,

.In order to illustrate the co-action and the opposed relations of theocclusal surfaces of these teeth, Figs. 9 to 15, inclusive, have beenillustrated to show the inter-relation at the points on the severalbucco-lingual section lines. In these figures, the dotted lines indicatethe primordial forms from which these first molars have been carved.

Figs. 16 to 19, inclusive, show the working side of the teeth in whichFig. 16 illustrates the closing of the teeth into lateral occlusionafter the mandible has moved from the centric position i C to theposition shown by the Fig. 17 shows the further operation of the teethto the point shown by the arrow in that figure, and wherein the buccaland lingual parts ofthebolus offoodareseparatedfromthecen-Gfi tralportion,

In Fig. 18, the mandible has moved as shown by the arrow in that figure,and the clearance sulci begin to open more and more from the positionshown in Fig. 17. '70

mandibular movements of mastication wherein the sharp-edged ridges onthe occlusal surfaces of the molars fulfill different tool-like cuttingactions on'the food. The arrows in these figures indicate the directionsin which these sharpedged ridges of the lower molars move against theridges of the upper molars.

The cross-wise principle of inter-action of these ridges during themandibular movements is most efficient and the retention of .theangulations and formation of the sulci and fossae" in the facet facesprovide means whereby these sharp-edged cutting ridges may be readilyprovided, so that cutting, shearing and grinding ismore readilyaccomplished with teeth of this The views shown in Figs. 28, 29,30 and31 are intended to illustrate the movements of the mandible in thedirection of the arrows, and the approach from the working bite tocentric position. These particular views illustrate the shearing actionwith the tool-like ridges formed on teeth asdescribed in thisapplication,

Figs. 32 to 35, inclusive, illustrate the manner of marking the buccalside of the posterior teeth to provide identifying means, whereby thedentist or other technician may properly place the teeth in a cast ormold, the first bicuspid having one collar 6!, the second bicuspid twocollars 62,

the first molar one collar 63. and the second molartwo collars 64. Theseidentifying means will also serve to identify teeth made according tothe invention disclosed herein, and are intended to be used in themanufacture of these teeth for the two purposes specified.

Of course, the teeth illustrated and described herein may be changedparticularly as to methads of providing the primordial form andangulations of the facets, etc., without departing from the inventionherein set forth and hereafter claimed.

The invention is hereby claimed as follows:

1. A posterior tooth having facets of varying 5 angulations toaccommodate average mandibular movements, said tooth having reliefs cutin the facets while retaining substantially the entire perimetersthereof, thus leaving the original meeting edges of the facets andthereby retain 1 ing the original facets angulations.

2. A posterior tooth having facets of varying angulations to accommodateaverage mandibular movements, said tooth having its facets provided withfossae of substantially the shape of the facets while retainingsubstantially the perimeters, of said facets, thus leaving the originalmeeting edges of the facets practically intact, and thereby retainingthe original control portions of said facets, and sulci leading fromsome t of the fossae and extending through the perimeters buccally andlingually.

' 3. A posterior tooth made from a primordial form having facets toaccommodate the average mandibular movements, said tooth having facetsprovided with fossae of substantially the shape of the facets whileretaining substantially the perimeters of said facets, thus leaving theoriginal meeting edges of the facets practically intact and therebyretaining the control portions which con- 3 form to average mandibularmovements.

4. Posterior teeth made from primordial forms having facets toaccommodate the average mandibular movements, said teeth having fossaein the facets while retaining substantially the 35 perimeters thereof;thus leaving the meeting edges of the facets practically intact andthereby retaining the control portions which conform to the averagemandibular movements, sulci leading from some of the fossae andextending through the perimeters buccally and lingually, said fossae andsulci so inter-related between the upper and lower teeth duringmasticating movements that the food is forced against the cutting edgesformed thereby -in order to cut and shear the same and expel masticatedfood hue- CERTIFICATE OF CORRECTION.

Patent No. 2,050,837. August 11, 1936.

ALFRED GYSI.

It is hereby certified that error appearsin the printed specification ofthe above numbered patent requiring correction as follows: Page 3,second column, .afterline 22, claim 2, insert the following as claims 3and 4:

3. A posterior tooth made from a primordial form having facets toaccomodate the average mandibular movements, said tooth having reliefsin the facets while retaining substantially the entire perimetersthereof, thusleaving the originalmeeting edges of the facets and therebyretaining the angulations of the primordial form.

4. A posterior tooth made from a primordial form having facets toaccommodate the average mandibular movements, said tooth having reliefsin the facets while retaining substantially the perimeters thereof,-thus leaving the' meeting edges of the facets practically intact andthereby retaining the control portions which conform to" averagemadibular movements.

The claims now appearing in the patent as numbers "3" and "4" shopldbear the numbers 5 and 6 respectively; and that the said Letters Patentshould be readwith these corrections therein that the same may conformto the record 01 the case in the Patent Office.

Signed and sealed this 29th day of December, A. D. 1956-.

Henry Van Arsdale (Seal) Acting Commissioner of Patents.

